Marantz MODEL 5 (1958–1963)

Name: Marantz MODEL 5
Brand: Marantz

Thirty watts of ultra-linear tube power in a chassis small enough to sit on the shelf. This was the monoblock that let working musicians and serious listeners buy into the Marantz name.

Overview

The Model 5 is a vacuum-tube monoblock power amplifier. That means one channel per chassis, so a stereo system takes a pair. Marantz released it in 1958. It carried the same design as the company's bigger Model 2, just in a smaller chassis with lower power output. The trade-off is less muscle and a more accessible price, and for a lot of owners the same essential character.

Marantz's own documentation describes the amplifier as running EL34 output tubes, and some sources also cite the KT77 as a substitute. It's rated at 30 watts (60 watts peak) in ultra-linear operation, and 18 watts when strapped into triode. That dual-mode setup made these amps interesting to hobbyists. You could run them hot and clean, or back them off and chase a sweeter midrange. Reports of "35 watts per channel" circulate in some owner videos, but the consistent figure across the technical sources is 30 watts, and that's the number to trust.

The wattage isn't what makes the Model 5 worth caring about. The construction is. It's dual-mono, hand-wired point-to-point, with a separate power supply for each channel, high-quality transformers, and front-panel bias adjustment meters. That last item matters more than it sounds. The built-in meter and test switch let you adjust each output tube's bias individually, so you don't need a matched quad to keep the amp running properly. For a 1958 design, that was a genuine convenience, and it's still the reason these amps are maintainable today.

Original price was $147 without the metal cage, or $154.50 with it. The cage was optional, and collectors chase it. A complete Model 5 with its original cage and documentation is a different animal from a bare chassis pulled out of a rack.

Key Features

Ultra-Linear EL34 Output Stage

The Model 5 runs EL34 output tubes in ultra-linear operation. That configuration taps the screen grids off the output transformer, splitting the difference between the efficiency of pentode mode and the linearity of triode. Marantz also documented a triode mode at 18 watts, which trades output power for a different harmonic character. The output tubes are fed by a 6BH6 and a 6CG7 in the driver and input stages. It's a modest tube complement, so replacement costs stay reasonable and sourcing is straightforward.

Front-Panel Bias Meter and Test Switch

One of the Model 5's most practical design choices is the built-in meter and test switch on the front panel. They allow accurate adjustment of each output tube's bias without pulling the chassis or attaching external test gear. Marantz's own documentation notes that this makes matched tubes unnecessary - you simply dial each tube in individually. There's also an adjustable A.C. balance preset on the subchassis, set at the factory.

Dual-Mono Construction and Point-to-Point Wiring

Each Model 5 is a single channel with its own power supply and its own transformer set, hand-wired point-to-point rather than built on a printed circuit board. That's why these amps have survived in serviceable condition for six decades. There's nothing to de-laminate, and every connection can be traced and re-soldered. The trade-off is weight and cost, both of which Marantz accepted in exchange for reliability and serviceability.

Speaker Impedance Flexibility

The output terminals offer 4, 8, and 16 ohms, so the Model 5 will drive just about any speaker load from the era, and most modern ones too. Input sensitivity is 1.3 volts RMS into 250 kohm. That suits tube preamps of the period and the Model 7 preamp that many owners paired it with.

Measured Performance

The documented frequency response runs 20 Hz to 20 kHz. Total harmonic distortion is listed at 0.1%, damping factor at 20, and signal-to-noise ratio at 90 dB. Those are respectable figures for a 1958 tube amplifier, and they explain why the Model 5 was treated as serious equipment rather than a budget side project. A damping factor of 20 is on the low side by later solid-state standards. That's normal for the era, and it's part of why these amps sound the way they do into high-efficiency speakers.

Historical Context

The Model 5 arrived in 1958, just as stereo was moving from the laboratory into the living room. Marantz positioned it as one of the company's earliest stereo-era designs, and the amplifier was built under the direct supervision of Saul Marantz. That ties the unit directly to the company's founding engineering culture.

Within the Marantz line, the Model 5 sat below the Model 2 in both size and output, and well below the Model 9 monoblocks that became the company's flagship pieces. Contemporary commentary framed the Model 5 as the accessible entry point: "a fraction of the price of their big brothers, the Model 9's," as one period-flavored description put it. Owners typically ran a pair of Model 5s with a Model 7 preamp, a combination that shows up repeatedly in the historical record.

At least one later review compared a restored pair of Model 5 monoblocks directly against a modern high-end amplifier, treating both as representative of the best of their respective eras. That's a lot of respect for a mid-tier product from 1958.

Collectibility & Value

The Model 5 sits in a strange spot in the market. It's respected enough to command real money, but not so famous that prices have gone completely irrational. Documented market values range from $2,000 to $5,000+ depending on condition and originality, with a collectibility rating of 9 out of 10. Recent eBay completed sales data is more granular: a high of $2,152, a median of $950, and a low of $375, based on a small sample of three sales over the past twelve months. Volume is thin, roughly one unit per month, so prices swing widely depending on what happens to be listed.

Current asking prices run considerably higher than the sold data. Restored and serviced monoblock pairs have been listed at $6,495, and a working original pair at $8,399. Specialist dealers have listed single units at $7,099.99. Those numbers reflect the premium that restored, cosmetically clean, and documented examples command — and the gap between asking and sold prices is a reminder that the Model 5 market rewards patience on both sides.

Maintenance is the usual tube-amp story. Capacitors dry out, resistors drift, and tubes lose their spark. A full recapping is almost always necessary on an unrestored unit, and a careful inspection of the transformers is wise, especially if the amplifier has been silent for years. Owners report finding failing screen grid resistors, which should be replaced with flameproof types. Once restored, the Model 5 needs ongoing attention: regular tube replacement, bias adjustments via the front-panel meters, and a careful hand during servicing.

For buyers, the details that matter most are originality and documentation. Examples with consecutive serial numbers, original owner's documents, and the optional metal cage are the ones that hold value. A restored unit with a few replaced capacitors is still desirable, since that's normal maintenance and not a red flag. A chassis that's been hacked or modified is a different proposition entirely.

One note for anyone searching: listings for a "Model 5 mk2 Speaker" occasionally appear alongside the amplifier. That's a separate product - a speaker, not the tube monoblock - and should not be confused with the amplifier discussed here.

Market Value

┌──────────────────────────────────────────────────────────────────────────┐
│ MARANTZ MODEL 5                                                 Nov 2026 │
├──────────────────────────────────────────────────────────────────────────┤
│ High      $2,152                                  Latest            $375 │
│ Median    $950                                    Trend                — │
│ Low       $375                                    Volume           ~1/mo │
├──────────────────────────────────────────────────────────────────────────┤
│ $3,000 ┤                                                                 │
│        │                                                                 │
│        │                                                                 │
│ $1,843 ┤.                                                                │
│        │                                                                 │
│        │                                                                 │
│        │                             .                                   │
│   $300 ┤                                                                .│
│        ├─────────────────────────────────────────────────────────────────│
│    vol │█                            █                                  █│
│        └─────────────────────────────────────────────────────────────────│
│         2026-04                      2026-05                      2026-07│
└──────────────────────────────────────────────────────────────────────────┘

eBay completed sales. Excludes accessories, parts, and non-working units. Hover points for details.